CGEM Alignment Pin Dims?

[Stargazer33]

Hi, I'm in the process of making an 'owls nest' mount head for a pier I intend to put up in the garden. I am going to mount an aluminium pier adapter on top of the stainless steel 'owls nest'. I have all the dimensions for the adapter except for the thread size of the alignment pin.

Any info would be gratefully appreciated. 😊

[Stargazer33]

I've managed to find the details. 

For those who wish to know it's M10 x 1.5 and approx 14mm long.

[newbie alert]

Have you got the pier plate?